Recognising seasonal affective disorder in chronic pain patients

Nobody likes the short, colder days
of the winter season. The concept that our mood fluctuates with the seasons has
been proposed for many centuries. For individuals suffering with chronic pain,
it can be even more of a problem. As we slowly move away from the dreary days
of winter, we are hopeful of being re-energised with the arrival of spring.
Unfortunately, for individuals with chronic pain with conditions such as
fibromyalgia, chronic fatigue syndrome or chronic myofascial pain, they might
take longer than most to recover from this seasonal dip in energy or increase
in pain symptoms.

Chronic pain is not
the only condition to show a seasonal variation. Rosenthal and colleagues
performed a series of bright-light therapy trials in 1980 and coined the term
‘seasonal affective disorder’ (SAD) and new interest in the condition was
generated.

Estimates of the
incidence of SAD in the general population suggest about 5 per cent of
individuals experience SAD annually. The true value of SAD in those with
chronic pain is unknown, but given that one-in-five individuals have chronic
pain, there is likely to be a significant overlap. When you consider the number
of individuals with fibromyalgia, chronic myofascial pain or chronic fatigue
syndrome, it is easy to imagine the impact the presence of SAD can have on
those with chronic pain.

What is SAD?

Features of SAD include being
irritable, exhausted, distracted, and withdrawn. These are features common to
many chronic pain suffers and it might be reasonable to attribute them to a
‘flare-up’ of the pain. But as clinicians, we need to be aware that we may be dealing
with something else and not just an incidental increase in the chronic pain
condition. If an individual reports low energy, weight gain and increased
sleep, then you need to consider the possibility of concurrent SAD. While the
diagnosis is made primarily on clinical grounds, SAD should be considered in
all people with recurrent affective disorders.

In addition to a
full history, there are several questionnaires that have been designed to aid
diagnosis. The Seasonal Pattern Assessment Questionnaire (SPAQ) is brief and is
the most widely used.

Epidemiology and aetiology

It appears that SAD lies on a
spectrum that can range between ‘normal’ seasonal changes, to actual SAD. For
example, two large community prevalence studies in the UK estimated 3.5 per cent
(in Aberdeen) and 2.4 per cent (in North Wales) of adults to be affected to a
level of clear clinical significance. Epidemiological studies in the US
estimate that its prevalence can range from 1.4 per cent of the adult
population in Florida, to 9.7 per cent in New Hampshire.

SAD is four times
more common in females of reproductive age. Individuals with a history (either
personal or familial) of depression or bipolar disorder, as well as those who
live far from the equator, seem to have a higher risk.

Interestingly,
there is a summer version of SAD as well. This is characterised by
restlessness, a decline in appetite, and insomnia. SAD is relatively rare in
children. In the older adult population, the ratio between males and females
with SAD tends to equalise.

Aetiological
theories of SAD include:

a) Exposure to daylight or photoperiods: Indicated by the seasonal nature of SAD and effects of photoperiods in other mammals and the effects of latitude of residence/moving away from the equator. There is some evidence that SAD sufferers are less exposed to natural light and that symptom fluctuations with changes in weather occur.

Recognising the symptoms of SAD can
be very important because it can direct the treatment options. Firstly, if SAD
is present and you are satisfied that it is not ‘just a flare-up in chronic
pain’, then increasing the pain medication is unlikely to help the individuals.
Secondly, because you can treat SAD with some simple steps, it is equally
important not to ignore some practical treatment options.

Effective treatment
options for SAD include:

a) Light therapy (or phototherapy)

For many, this is the first-line of
treatment for SAD. After waking up in the morning, patients sit approximately
18 inches from a light box — an illuminated device that should emit 10,000 lux of
strong white light and very little ultraviolet (UV) light — for 30-to-45 minute
sessions. A two-week course of treatment is usually effective.

Initially, 5,000
lux hours/day is recommended. This is most effective if given in the morning,
but time may be ‘topped-up’ in the afternoon if this is practical. Bright-light
treatment should not be taken at night, as it can induce insomnia. These
portable devices are readily available to purchase and range in price from
€35-to-50.

Side-effects are
uncommon and generally well tolerated. The most common adverse effects are
headache and blurred vision. Advice about not looking continuously and directly
into the light often is beneficial. There are no known cases of ocular damage
with bright-light therapy.

There are
alternatives to light boxes. In particular, dawn-simulating alarm clocks have
been shown to be effective and may facilitate treatment adherence. Some
individuals find that having a winter sunshine holiday is enough to offset the
SAD.

b) Medication

As with all medication there are
advantages and disadvantages and sometimes a balance has to be found that suits
each individual’s needs. Duloxetine is an antidepressant included in the
pharmacological class of serotonin-norepinephrine reuptake inhibitors (SNRIs)
approved for the treatment of major depressive disorder, generalised anxiety
disorder, diabetic peripheral neuropathic pain, fibromyalgia, and chronic
musculoskeletal pain. There is now some evidence that it may be an effective
treatment for mood spectrum disorders (Frontiers Psychiatry 2019).

Other
antidepressants are also used to treat SAD; popular options include SSRIs,
particularly fluoxetine and bupropion.

As with any
medication targeting moods it is important to consider the overall well-being
of the individual before committing to this option. It may be possible to use
this style of medication to help an individual with chronic pain get over the
seasonal issues but it may take a few weeks for the medication to help so it
needs to be considered in advance.

c) Vitamin D

Vitamin D is produced by the body
after exposure to the sun, therefore people tend to have lower vitamin D levels
in the winter. Supplementation of this vitamin (either through foods or
supplements) could help alleviate SAD symptoms. As it has also become easier to
measure vitamin D levels it may be of benefit to measure a baseline level and
monitor the pattern in your patients with chronic pain.

There have not been
many studies researching vitamin D’s impact on SAD; some researchers have found
a link between low levels of vitamin D in the blood and depression. Low vitamin
D levels have been reported in chronic pain patients including fibromyalgia and
chronic pain syndromes. There has been some interesting recommendations, such
as Stewart B Leavitt writing in Practical Pain Management, who feels that a
“vitamin D supplement may help patients cope with chronic pain”. This approach
is simple and practical. Taking vitamin D as a single tablet or in conjunction
with a multivitamin is a practical step we could all consider.

d) Melatonin:

Researchers published in the Proceedings of the
National Academy of Science have found that low-dose melatonin,
a naturally occurring brain substance might be another way to treat SAD. It is
proposed SAD stems from “a mismatch” between your circadian rhythms and your
sleep/wake cycle (ie, the cycle dictated by your alarm clock).

The time and dose
used is important. Lewy et al recommend taking around 0.5mg of
melatonin, which is just above what the body naturally produces at night, but
about 1/10 the normal dose sold in stores seems adequate. Some individuals who
are particularly susceptible to the sleep-inducing effects of melatonin – even
at low doses – shouldn’t drive after taking the supplement. Taking the dose in
the late afternoon might be the best option.

e) Cognitive behavioural therapy (CBT):

This form of psychotherapy involves
the therapist working with the individual to help the sufferer identify and
understand ways of thinking that may be obstacles to improving their mood,
thereby increasing the ability of the person with SAD to alleviate symptoms. In
CBT, trained clinicians encourage patients to challenge unhelpful thought
patterns and become more active and engaged with others, as well as plan for
future SAD episodes. This technique is practical and offers the individual the ability to respond to
their symptoms in a timely fashion.

f) Physical activity:

Exercise is always to be recommended.
Physical fitness lends us to produce natural endorphins (pain-relieving
hormones) that can help boost moods. In fact, a lack of exercise could be one
reason for a possible link between chronic pain and SAD symptoms. Physical
activity is recommended for the relief of many pains from lower back pain to
fibromyalgia to arthritis.

With the long dark
evenings people tend to be more
sedentary during the winter, and that can lead to feelings of low
self-confidence and unhappiness. In an English study with almost 2,500 people,
respondents were most likely to experience pain in the winter.

There are many ways
to encourage individuals to be active even during the winter months: Follow an
exercise class online or on television, meet a friend for indoor tennis or a
yoga class, incentivise things by setting up – and paying for – a gym
membership. The importance of exercise cannot be overstated especially as we
turn into the spring. Adding physical activity to your treatment prescription
at this time of year for your patients will offer them the best opportunity
to control the symptoms of SAD and
chronic pain.

Overall

If an individual with a chronic pain
condition, such as fibromyalgia, presents with an increase in tiredness,
irritability or the altered mood and sleeping pattern it may not just be a
‘flare up’ of their chronic pain condition that is to blame. A diagnosis of SAD
should be considered and it can be very reassuring that it is not just their
chronic pain but a separate condition. By recognising the concurrent presence
of SAD in those with chronic pain you may be providing very effective pain
management treatment.